Using parameters in Actions

I need to do an add_action to a signup function, but my function is going to need all the values of from signup. How do I pass a parameter to my function, even if it's just the new blog id, which I can use to get everything else? I don't see any way of passing a parameter to an action/filter function.

In fact, is the blog Id even available on signup or is created once the blog is activated?



    Thanks, I think that might work. Great example! I think I can use the user_id to get what I need because I actually store all my fields in the meta property of the signup. I modified the wp-signup.php file directly (had no choice) so I put them there. Like your PayToBlog plugin, I can read it out of the signup from within the function I hook to wpmu_new_blog and write it to my table. I'll try it.

    In short, I store a lot of field with the signup and didn't want to append them all together into the custom field of the PayPal request (just storing blog_id) so I'm writing them to my own table (one-to-one with wp_blogs). When PayPal returns, it will give me the blog id which I can use to get all my data back.

    Thanks again about wpmu_new_blog. Very good to know.